This invention relates to a polyester carbonate containing imido groups which is excellent in mechanical strength and molding processability and also has liquid crystal characteristic and to a process for producing the same.
Polyester carbonates are generally excellent in physical properties such as mechanical properties, heat resistance, chemical resistance, etc., and are useful as the materials for molded product in general for which high strength is not required.
However, a polyester carbonate having a structure known in the art, for example, one having the repeating units of ##STR3## and --O--Ar--OCO-- cannot be said to have satisfactory strength as the material for molded products in the field for which high strength is demanded.
An object of the present invention is to avoid the problem as mentioned above and to provide a polyester carbonate which is useful also as the material for molded products in the field for which high strength is demanded.